This invention relates to a light source unit having a plurality of arrayed light sources such as LED's and a projection type video display apparatus in which the intensity of light from the light source unit is modulated by means of a video display device formed of, for example, transmission or reflection type liquid crystal or DMD (small mirror) and an optical image thus formed is projected.
A projection type video display apparatus as represented by a liquid crystal projector has hitherto been known in which light from a light source is caused to impinge upon a video display device such as liquid crystal panel and an image on the liquid crystal panel is projected in enlarged size.
Many products of a projection type video display apparatus using a light source formed of a single lamp or a plurality of lamps each capable of being supplied with high power for the purpose of increasing brightness have hitherto been manufactured but recently, a trend toward the application of a so-called LED light source such as light emitting diode, organic EL or the like has been studied because of its good color purity, long lifetime and good lighting capability. In this case, to supplement a shortage of brightness, many arrayed LED light sources are often used. For example, JP-A-2002-374004 discloses this type of LED light source unit and a projection type video display apparatus using the same.
Recently, as disclosed in, for example, JP-A-2002-151746, a reflection type LED has also been proposed in which light from an LED is reflected by a concave reflection mirror so as to be delivered forwardly. In addition, JP-A-2003-329978, for example, discloses an LED light source unit having reflection type LED's of this type arranged in matrix and a projection type video display apparatus using the same.